The first time that Olympic swimmer Allison Schmitt considered suicide was in January 2015, when she was driving from Baltimore to Penn State to watch her twin sisters play in a women’s hockey game.

It was a cold, snowy night, and she had to fight hard to keep her dark thoughts at bay long enough to enjoy the game with her family.

By this point, Allison had been struggling with depression for over two years, ever since she returned from the 2012 Olympics in London, where she’d won five medals for the U.S. Olympic Swimming Team. She was welcomed back with congratulations and support, and people telling her that they wished they were her. Her reaction? “I wish I felt that way.”

Nobody knew about Allison's depression—not even her family. “I didn’t want to complain, because I knew I was lucky, and I knew I was in a spot where not many people get to be,” she tells Women's Health. “And I didn’t understand why I would be feeling like that. I always thought that people who struggled had a traumatic event that happened to them or they had a reason to struggle. I had a picture-perfect life.”

As an athlete in the international spotlight, she felt the need to keep up an appearance of happiness, excitement, and gratitude. She equated her negative feelings to other troubles you might encounter in life, in school, and in swimming—just keep working, keep pushing, and it’ll get better. “From a young age, I was taught to persevere and to push through and you’ll be stronger.” But she didn’t feel stronger.

One person had noticed a change in her, though: Michael Phelps. A few weeks after her trip to Penn State in 2015, she was competing in a Grand Prix meet, where Michael Phelps was watching. As a close friend, he had noticed she was different—her attitude, her racing, everything. Allison says Michael approached her and said, “I know there’s something going on, and if you’re ready, I am here to talk to you, or I can get someone else to help you.”

Allison broke down in tears. She says that was the first time she recognized she needed help. She started seeing a psychologist, but still none of her friends or family knew—just Michael and her coach Bob Bowman. Michael had experienced his own dark times, telling Sports Illustrated that he didn't want "to be alive anymore" after his DUI arrest in 2014.

Flash forward a few months to May 2015, when Allison’s 17-year-old cousin April committed suicide. The news struck Allison hard—April, a high school basketball star, was so happy, so loved by everyone. “How were those demons so dark inside of her that she couldn’t bear it?” she says. “But I didn’t know. No one knew. And I thought, if she would’ve spoken about it, if we knew that we were both struggling, could we have helped each other?”

That’s when she decided it was time to speak publicly about her struggle with depression. It was tough at first (she broke down during an interview with reporters), but Allison says it got easier over time. “I hate public speaking because I get really nervous, but when I’m speaking about mental health, I can do it easily because I am so passionate about that,” she says.

Allison now travels around the country to speak at schools, and attends events and galas that support mental health awareness. She recently attended the gala for the American Foundation for Suicide Prevention, and on May 15, she’ll be speaking at a Mental Health Awareness panel on Instagram Live with Women’s Health Editor-in-Chief Amy Keller Laird, Barbara Ricci from the National Alliance on Mental Health, Elyse Fox, founder of Sad Girls Club, and Carolyn Merrell, who handles public policy at Instagram.

Her overall goal is to educate people about mental illness. She hopes to get more conversations started so that people know they don’t need to act like everything’s okay, and that they have allies. “Being vulnerable is not weakness,” she says. “It shows you are strong enough to know that life is sometimes hard for you to handle and you need support.”